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Pregnant women are exposed to multiple phthalates and their replacements, which are endocrine disrupting chemicals associated with adverse maternal and child health outcomes. ...Identifying maternal characteristics associated with phthalate/replacement exposure during pregnancy is important.
We evaluated 13 maternal sociodemographic and lifestyle factors, enrollment year, and conception season as determinants of exposure biomarkers of phthalates and their replacements in 482 pregnant women from the Illinois Kids Development Study (I-KIDS, enrolled 2013–2018). We quantified 19 phthalate/replacement metabolites in pools of five first-morning urines collected across pregnancy. K-means clustering identified women with distinct patterns of biomarker concentrations and principal component analysis (PCA) identified principal component (PC) profiles of biomarkers that exist together. We used multivariable regression models to evaluate associations of predictors with identified k-means clusters and PCs.
K-means clustering identified two clusters of women: 1) low phthalate/di(2-ethylhexyl) terephthalate (∑DEHTP) and 2) high phthalate/∑DEHTP biomarker concentrations. PCA identified four PCs with loadings heaviest for biomarkers of plasticizer phthalates di-isononyl, di-isodecyl, di-n-octyl phthalates (PC1), of other phthalates dibenzyl, di-n-butyl, di-iso-butyl phthalates (PC2), of phthalate replacements ∑DEHTP, di(isononyl) cyclohexane-1,2-dicarboxylate (∑DiNCH) (PC3), and of monoethyl phthalate MEP (PC4). Overall, age, marital status, income, parity, pre-pregnancy BMI, caffeine intake, enrollment year, and conception season were independently associated with k-means cluster membership and at least one PC. Additionally, race/ethnicity, education, employment, pregnancy intention, smoking status, alcohol intake, and diet were associated with at least one PC. For instance, women who conceived in the spring, summer, and/or fall months had lower odds of high phthalate/∑DEHTP cluster membership and had lower plasticizer phthalate, phthalate replacement, and MEP PC scores.
Conception season, enrollment year, and several sociodemographic/lifestyle factors were predictive of phthalate/replacement biomarker profiles. Future studies should corroborate these findings, with a special focus on replacements to which pregnant women are becoming increasingly exposed.
Summary Background The poor health of South Africans is known to be associated with a quadruple disease burden. In the second National Burden of Disease (NBD) study, we aimed to analyse cause of ...death data for 1997–2012 and develop national, population group, and provincial estimates of the levels and causes of mortality. Method We used underlying cause of death data from death notifications for 1997–2012 obtained from Statistics South Africa. These data were adjusted for completeness using indirect demographic techniques for adults and comparison with survey and census estimates for child mortality. A regression approach was used to estimate misclassified HIV/AIDS deaths and so-called garbage codes were proportionally redistributed by age, sex, and population group population group (black African, Indian or Asian descent, white European descent, and coloured of mixed ancestry according to the preceding categories). Injury deaths were estimated from additional data sources. Age-standardised death rates were calculated with mid-year population estimates and the WHO age standard. Institute of Health Metrics and Evaluation Global Burden of Disease (IHME GBD) estimates for South Africa were obtained from the IHME GHDx website for comparison. Findings All-cause age-standardised death rates increased rapidly since 1997, peaked in 2006 and then declined, driven by changes in HIV/AIDS. Mortality from tuberculosis, non-communicable diseases, and injuries decreased slightly. In 2012, HIV/AIDS caused the most deaths (29·1%) followed by cerebrovascular disease (7·5%) and lower respiratory infections (4·9%). All-cause age-standardised death rates were 1·7 times higher in the province with the highest death rate compared to the province with the lowest death rate, 2·2 times higher in black Africans compared to whites, and 1·4 times higher in males compared with females. Comparison with the IHME GBD estimates for South Africa revealed substantial differences for estimated deaths from all causes, particularly HIV/AIDS and interpersonal violence. Interpretation This study shows the reversal of HIV/AIDS, non-communicable disease, and injury mortality trends in South Africa during the study period. Mortality differentials show the importance of social determinants, raise concerns about the quality of health services, and provide relevant information to policy makers for addressing inequalities. Differences between GBD estimates for South Africa and this study emphasise the need for more careful calibration of global models with local data. Funding South African Medical Research Council's Flagships Awards Project.
Phosphorus fractions in leaves Suriyagoda, Lalith D. B.; Ryan, Megan H.; Gille, Clément E. ...
The New phytologist,
February 2023, Letnik:
237, Številka:
4
Journal Article
Recenzirano
Summary
Leaf phosphorus (P) comprises four major fractions: inorganic phosphate (Pi), nucleic acids, phospholipids, P‐containing metabolites and a residual fraction. In this review paper, we ...investigated whether allocation of P fractions varies among groups of terrestrial vascular plants, and is indicative of a species' strategy to use P efficiently. We found that as leaf total P concentration increases, the Pi fraction increases the most, without a plateau, while other fractions plateau. Variability of the concentrations of leaf P fractions is greatest among families > species(family) > regions > plant life forms. The percentage of total P allocated to nucleic acid‐P (20–35%) and lipid‐P (14–34%) varies less among families/species. High photosynthetic P‐use efficiency is associated with low concentrations of all P fractions, and preferential allocation of P to metabolite‐P and mesophyll cells. Sequential resorption of P from senescing leaves starts with Pi, followed by metabolite‐P, and then other organic P fractions. Allocation of P to leaf P fractions varies with season. Leaf phytate concentrations vary considerably among species, associated with variation in photosynthesis and defence. Plasticity of P allocation to its fractions is important for acclimation to low soil P availability, and species‐specific P allocation is needed for co‐occurrence with other species.
The use of acid soil‐tolerant annual legume pasture species and liming to raise soil pH can have legacy effects that improve subsequent wheat crop growth in acid soils. We established a two‐year ...experiment in a semi‐arid environment with and without historical lime application to investigate how acid soils (±lime) influence the legacy effects of annual legume pastures. We measured legume and cereal growth and yield, soil‐borne disease incidence, rhizosheath organic acid type and amount, legume biological nitrogen fixation (BNF) and soil moisture in Year 1, and soil microbial biomass carbon (MBC) and wheat yield and quality in Year 2. Minor differences in soil moisture and soil‐borne diseases occurred between cereals and legumes, and the poor BNF contribution of all pasture legumes improved in lime treatments. Pasture legumes produced more organic acids than cereals, which increased in limed treatments. Soil MBC in Year 2 was greater following legumes than cereals. Year 2 wheat grain yield increased following pasture legumes, more so in limed treatments. The contribution of organic acid exudation by annual legume pastures to microbial community legacy effects warrants further scrutiny in semi‐arid environments, particularly when acid soils limit typical rotational benefits.
Purpose: Auditory processing measures have been used in an attempt to understand the relationship between neurological mechanisms and autism spectrum disorder (ASD) symptomatology in school-age ...children. The focus of the current study was to understand neural auditory processing in 2- to 3-year-olds with ASD. Method: Auditory processing measures (click auditory brainstem responses and speech-evoked frequency-following responses) were hypothesized to differ between typically developing children (n = 18) and children with ASD (n = 18). Auditory processing measures were hypothesized to relate to language development in children with ASD. Results: The current study found limited differences in auditory processing measures between the two groups. No relationships were found between auditory processing measures and language development measures. Conclusions: Future research is necessary to characterize auditory processing in toddlers with ASD. Longitudinal approaches should be considered when studying auditory processing in children with ASD in order to explore its developmental relationship with ASD symptomatology.
Biodiversity offsets aim to counterbalance the residual impacts of development on species and ecosystems. Guidance documents explicitly recommend that biodiversity offset actions be located close to ...the location of impact because of higher potential for similar ecological conditions, but allowing greater spatial flexibility has been proposed. We examined the circumstances under which offsets distant from the impact location could be more likely to achieve no net loss or provide better ecological outcomes than offsets close to the impact area. We applied a graphical model for migratory shorebirds in the East Asian–Australasian Flyway as a case study to explore the problems that arise when incorporating spatial flexibility into offset planning. Spatially flexible offsets may alleviate impacts more effectively than local offsets; however, the risks involved can be substantial. For our case study, there were inadequate data to make robust conclusions about the effectiveness and equivalence of distant habitat‐based offsets for migratory shorebirds. Decisions around offset placement should be driven by the potential to achieve equivalent ecological outcomes; however, when considering more distant offsets, there is a need to evaluate the likely increased risks alongside the potential benefits. Although spatially flexible offsets have the potential to provide more cost‐effective biodiversity outcomes and more cobenefits, our case study showed the difficulty of demonstrating these benefits in practice and the potential risks that need to be considered to ensure effective offset placement.
Estudio de los riesgos y beneficios de la flexibilidad en la ubicación de compensación de la biodiversidad en el estudio de caso de aves costeras migratorias
Resumen
Las compensaciones de la biodiversidad buscan contrabalancear el impacto residual que tiene el desarrollo sobre las especies y los ecosistemas. Los documentos guía recomiendan explícitamente que las acciones de estas compensaciones estén ubicadas cerca del lugar del impacto debido al potencial elevado de que haya condiciones ecológicas similares, aunque ya hay propuestas de una mayor flexibilidad espacial. Analizamos las circunstancias bajo las cuales las compensaciones alejadas del lugar de impacto tendrían mayor probabilidad de lograr pérdidas netas nulas o de proporcionar mejores resultados ecológicos que las compensaciones cercanas al área de impacto. Aplicamos un modelo gráfico para las aves costeras migratorias en el corredor aéreo asiático‐australasiático del este como estudio de caso para estudiar los problemas que surgen cuando se incorpora la flexibilidad espacial a la planeación de las compensaciones. Las compensaciones espacialmente flexibles pueden mitigar los impactos más efectivamente que las compensaciones locales; sin embargo, los riesgos que esto involucra pueden ser considerables. En nuestro estudio de caso hubo datos insuficientes para concluir contundentemente sobre la efectividad y equivalencia de las compensaciones basadas en los hábitats distantes para las aves costeras migratorias. Las decisiones en torno a la ubicación de las compensaciones deberían estar impulsadas por el potencial para obtener resultados ecológicos equivalentes; sin embargo, al considerar compensaciones más alejadas, existe la necesidad de evaluar el incremento probable de riesgos junto a los beneficios potenciales. Aunque las compensaciones espacialmente flexibles tienen el potencial para proporcionar resultados más rentables y más beneficios colaterales, nuestro estudio de caso mostró la dificultad para demostrar estos beneficios en la práctica y los riesgos potenciales que necesitan considerarse para asegurar una ubicación efectiva de las compensaciones.
【摘要】
生物多样性补偿旨在抵消发展对物种和生态系统的残留影响。生物多样性补偿的指导文件明确建议, 补偿行动应在受影响地点的附近进行, 因为相似的生态条件具有较大的补偿潜力, 但也有人提出补偿地点的选择应允许更高的空间灵活性。我们研究了在什么情况下, 远离影响地点的补偿行动比靠近影响地点的补偿行动更有可能实现无净丧失或产生更好的生态结果。本研究以迁徙滨鸟在东亚‐澳大利亚的飞行路径为例, 应用图形模型探究了将空间灵活性纳入生物多样性补偿规划时出现的问题。空间上灵活的补偿有可能比原地点附近的补偿更有效地减缓影响;然而, 也可能涉及巨大的风险。在我们的案例研究中, 没有足够的数据来对远距离的基于栖息地的迁徙滨鸟生物多样性补偿的有效性和等价性做出有力结论。补偿地点的选择应该由实现等价生态结果的潜力所驱动;然而, 当考虑更远距离的补偿时, 还需要评估可能增加的风险和潜在的好处。虽然空间上灵活的补偿有可能提供更具成本效益的生物多样性结果和更多的共同利益, 但我们的案例研究表明, 在实践中证明这些利益尚面临困难, 研究同时指出了为确保补偿地点的有效性需要考虑的潜在风险。【翻译:胡怡思;审校:聂永刚】
Crops with improved uptake of fertilizer phosphorus (P) would reduce P losses and confer environmental benefits. We examined how P‐sufficient 6‐week‐old soil‐grown Trifolium subterraneum plants, and ...2‐week‐old seedlings in solution culture, accumulated P in roots after inorganic P (Pi) addition. In contrast to our expectation that vacuoles would accumulate excess P, after 7 days, X‐ray microanalysis showed that vacuolar P remained low (<12 mmol kg−1). However, in the plants after P addition, some cortex cells contained globular structures extraordinarily rich in P (often >3,000 mmol kg−1), potassium, magnesium, and sodium. Similar structures were evident in seedlings, both before and after P addition, with their P increasing threefold after P addition. Nuclear magnetic resonance (NMR) spectroscopy showed seedling roots accumulated Pi following P addition, and transmission electron microscopy (TEM) revealed large plastids. For seedlings, we demonstrated that roots differentially expressed genes after P addition using RNAseq mapped to the T. subterraneum reference genome assembly and transcriptome profiles. Among the most up‐regulated genes after 4 hr was TSub_g9430.t1, which is similar to plastid envelope Pi transporters (PHT4;1, PHT4;4): expression of vacuolar Pi‐transporter homologs did not change. We suggest that subcellular P accumulation in globular structures, which may include plastids, aids cytosolic Pi homeostasis under high‐P availability.
We examined clover roots after inorganic phosphorus (Pi) addition. Although vacuolar P concentration was unchanged, unexpectedly, P accumulated in intracellular globular structures and genes similar to plastid envelope Pi transporters were up‐regulated. The structures likely aid cytosolic Pi homeostasis.
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